IM-P403-89
EMM Issue 8
42
6.4.6 INPUT sub menu notes
6.4.6.1
INPUT – TDS – SENSOR
– FLT MODE
Only shown if the CP32 probe is selected.
Allows selection of the action to be taken if the probe detects a fault.
'OFF'
No action.
'CLEAN'
If the probe is scaled then the time between probe conditioning cycles will
change from the CLEAN-INTERVAL time set to 10 minutes, until the probe
is clean. The display will flash 'CLEANING' during the conditioning cycle.
'ALARM'
Alarm relay released, and the display will flash 'SCALED'.
'AL + CLEAN'
Recommended setting – alarm relay released, display shows 'SCALED', and
the probe conditioning circuit is activated.
The fault will be recorded in the error menu.
Caution:
The probe may be damaged if 'cleaning
every 10 minutes' is allowed to continue for long periods. The probe should be examined and
mechanically cleaned after 12 hours of 'fault condition'.
Note:
Certain probe / wiring faults will also trigger the probe scale detect feature.
6.4.6.2
INPUT – TDS –
PURGE
Used only when the probe is mounted in the blowdown line,
Purge
ensures the sensor
measures the conductivity at boiler temperature.
Note
If the purge time is set to any figure other than zero, the controller will automatically limit the
cleaning (conditioning) time to 9 seconds (max.) to avoid bubbles forming on the probe during
the purge, and causing an inaccurate reading. The display will also only be updated when
the blowdown valve is open. This means that when the controller is switched on, the display
will show the last valid reading until the next purge.
6.4.6.3
INPUT – TDS – PURGE –
DURATION
The duration is the time the valve is open to enable a representative boiler sample to reach
the probe. The duration time is set to zero if the probe is installed in the boiler or for a CCD
system. On BCS1 and BCS4 systems, 30 seconds is normally sufficient time to ensure the
sensor reaches boiler temperature. Where a slow-opening valve is used, or where there is
long or large bore pipework between the boiler and the sensor, a longer purge time will be
required. Alternatively the time can be manually entered from 000 (default) to 180 seconds
in 1-second steps.
To manually find the best purge time:
-
Allow the blowdown pipework to cool for 15 minutes.
-
Set the purge time to 60 (or greater if required) and calibrate the controller.
-
Note the time taken for the display to stabilise. Set this time as the purge time. Enter a
manual duration time from 000 (default) to 180 seconds in 1-second steps.
6.4.6.4 INPUT – TDS – PURGE – INTERV
AL
/
B
URNER
Note:
This feature is not visible if the duration is set to zero (i.e. sensor in boiler). Interval is
the time between purges.
Interval can be set between 10 to 60 minutes either independent of burner firing, (
normal
)
or dependant on cumulative boiler firing time (
cumulative
).
Summary of Contents for BC3250
Page 76: ...IM P403 89 EMM Issue 8 76...
